Each day a different image or photograph is featured, with an
accompanying caption, which deals with various topics in Earth Science.

Iridescence Over Estonia

The above photo showing the unmistakable pastel coloration of iridescent clouds was taken on July 21, 2005 above Viimsi, Estonia. Referred to also as irisation or opalescence, this phenomenon results from diffraction of sunlight, which is essentially the deflection of light around cloud droplets -- a result of the wave properties of light. Iridescent clouds are basically detached coronae, thus they're observed in in the vicinity of the Sun in low and mid altitude clouds.